In Singapore Buses on iOS 26, I was able to hide the tabViewBottomAccessory based on various criteria—for example, if location tracking was enabled.

.tabViewBottomAccessory {
    if locationTracker.isAuthorised {
        HStack {
          // Nearby bus stop
        }
     } else {
         EmptyView()
     }
}

Now, however, it displays the accessory with no content. I haven’t found a workaround yet, so for now I’m showing the tabViewBottomAccessory across all views. This isn’t ideal—the accessory isn’t relevant on the Settings view, for instance.

If this is Apple’s intended behaviour for the accessory, it’s far from ideal.